<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
    <style>
      .box1 {
        width: 200px;
        height: 200px;
        background-color: orange;
        font-size: 40px;
        opacity: 0.5;
        font-weight: bold;
      }
    </style>
  </head>

  <body>
    <div class="box1">你好啊</div>
  </body>
</html>
